Risk Factors

• Corticosteroids• Existing arthritis• Articular infection• Infection elsewhere• DM• Trauma• None

Frequency of Joints

• Knee• Hip• Ankle• Elbow• Wrist• Shoulder• Sternoclavicular

Pathology

• High vascularity• S. aureus collagen-binding adhesin associated with osteomylitis but not septic joint

• Disruption of normal joint by pre-existing joint disease

• Proteolytic enzymes released

Signs and Symptoms

• Joint pain, swelling, warmth, and decreased range of motion

• Joint tenderness to pressure or movement

• Tendon tenderness• Fever• May resemble acute crystal dz. or hemothrosis

Organisms Associated

• Neisseria-1-12%• Non-gonorrhea-S. aureus-37-56%, Streptococcal-10-28%, GNR-4-19%, coagulase negative staph-5%, anaerobic-2%, PMB-less than 10%

• Am Rheum Disease-2002, 61:267

Septic Arthritis-odd organisms

• Lyme, Mycoplasma• Listeria, enterococcus, chlmydia• M. tuberculosis, atypical Tb• Candida, sporothrix, blastomycosis, coccidiom\

• Rubella, hep b and c, EBV, parvovirus, mumps

Synovial Effusion

• Normal-clear, viscous, colorless-<200 wbc (<25% pmns)

• Noninflammatory-clear, viscous, yellow 200-2000 wbc-<25% pmns

• Inflammatory-cloudy, watery, yellow-2000-50,000 cells (>50% polys)

Synovial Effusion, continued

• Infected-purulent->50,000 cells (>75% pmns)

• Great overlap at times

Gonococcal vs. non gc Arthritis

• Gc-sexually active adults, migratory polyarthralgias, tenosynovitis, dermatitis common, >50% polyarthritis, BC positive <10%, joint fluid positive 25%

GC vs. non GC

• Non GC-very young or elderly, polyarthralgias, tenosynovitis rare, dermatitis rare, >85% monoarthritis, BC positive 50%, joint fluid positive 85-90%

• NEJM-1985, 312:764-771

Outcome of Bacterial Arthritis

• 154, 121 adults-half had joint disease

• 29% of joints contained synthetic material

• Poor outcome in 21% of patients• Poor joint outcome in nearly 50% of patients

Outcome continued

• Risk factors for poor outcome include-older age, existing joint disease, synthetic joint

• Arthritis and Rheumatism• 1997, 40:884.

Factors Associated with Poor Prognosis

• Age >60 years• Pre-existing rheumatoid arthritis or hip or shoulder infection

• >1 week of infection• >4 joints involved• Positive cultures after 7 days of appropriate treatment

Management

• Antimicrobials do achieve adequate levels in joint fluid

• Joint effusion drainage necessary but best method to drain is uncertain

Prosthetic Hip Infxns, Organisms

• Gram positive-CNSE>S. aureus>streptococcus>enterocc

• Gram negative-Enteric>pseudomonas

• Anaerobes least common• J Bone Jt. Surg-1996, 78:512

Results of Rx of Infxns-Prosthetic Hip • Positive intraoperative-28/31 good outcome (90%) 3.5 year followup

• Early Postoperative 25/35 (71% good outcome) 3.3 yrs followup

• Late chronic-29/34 (85%) good outcome-2.6 years followup

Results of Treatment continued

• Acute hematogenous-3/6 (50%) good outcome-2.6 years followup

• Journal Bone and Joint Surgery 1996, 78:512

Prosthetic Joint Infection

• Positive intraoperative cx-6 weeks iv with no surgical Rx

• Early (one month)-surgical, remove lines, leave bone components, 4 weeks iv antibiotics

Prosthetic Joint Infection

• Late chronic infection-debridement, remove components and cement, 6 weeks iv antibiotics

• Acute hematogenous-treatment same as early postoperative, replace components if loose

• J Bone Jt Surg 1995, 77: 1576

Rifampin Containing Regimens

• Proven S. aureus or coagulase negative staph infxns.

• Stable joint with sms less than 21 days

• Initial debridement and 2 weeks of antistaph followed by oral for 3 months if hip or 6 months if hip

Rifampin Containing Regimens

• 12/12 cured with cipro+rifampin

• 7/12 cured with cipro plus placebo

• JAMA-1998, 279, 1537• Lancet 2001, 1:175.

Suppression with oral

• In one study of patients who were high risk/poor function if joint removed-treatment mean was 37.6 months

• 10/13 patients required prothesis removal for recurrent infections (mean 21.6 months

Suppression-continued

• Conclusion-benefits are limited

• Orthopaedics-1991, 14:841.

Osteomyelitis classification

• Cierny and Mader-Orthopaedic Review-1987, 16:259

• I-medullary, II-superficial, III-localized, IV-diffuse

• Host factors-A-normal, B-compromised, C-prohibitive

• Waldvogel-NEJM-1970, 282:198• Hematogenous, continguous

Osteomyelitis diagnosis

• Staging studies-MRI, CT, nuclear scans, ESR, CRP, bone biopsies and cultures

Osteomyelitis treatment

• Surgery and antibiotics• Controversies in length of treatment, etc.

Diabetic Foot

• MRI-99% sensitive, 83% specific• Plain x-ray-60% sensitive, 66% specific

• Tc99m bone scan-86% sensitive, 45% specific

• In111 WBC-89% sensitive, 78% specific, CID 1997: 25: 1318

Probing to Bone

• Technique to determine bone infection

• Sterile, steel probe used• positive test if bone can be touched with probe

• Sensitivity-89%, specificity-85% JAMA-1995. 273:721

Diabetic Foot

• 254 isolates from 96 patients• S. aureus-38 isolates, Enterococcus-31, peptostreptococcus-31, CNSE-27, streptococcus sp-27, proteus-10, klebsiella-10

• CID-1995, 20 (supplement 2).